[PATCH] [net] fix inaccuracies in msg_zerocopy.rst

[PATCH] [net] fix inaccuracies in msg_zerocopy.rst

[nick black]

Replace "sendpage" with "sendfile". Remove comment about
ENOBUFS when the sockopt hasn't been set; experimentation
indicates that this is not true.

Signed-off-by: nick black <dankamongmen@gmail.com>
---
 Documentation/networking/msg_zerocopy.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git Documentation/networking/msg_zerocopy.rst Documentation/networking/msg_zerocopy.rst
index 15920db8d35d..b3ea96af9b49 100644
--- Documentation/networking/msg_zerocopy.rst
+++ Documentation/networking/msg_zerocopy.rst
@@ -15,7 +15,7 @@ Opportunity and Caveats
 
 Copying large buffers between user process and kernel can be
 expensive. Linux supports various interfaces that eschew copying,
-such as sendpage and splice. The MSG_ZEROCOPY flag extends the
+such as sendfile and splice. The MSG_ZEROCOPY flag extends the
 underlying copy avoidance mechanism to common socket send calls.
 
 Copy avoidance is not a free lunch. As implemented, with page pinning,
@@ -83,8 +83,8 @@ Pass the new flag.
 	ret = send(fd, buf, sizeof(buf), MSG_ZEROCOPY);
 
 A zerocopy failure will return -1 with errno ENOBUFS. This happens if
-the socket option was not set, the socket exceeds its optmem limit or
-the user exceeds its ulimit on locked pages.
+the socket exceeds its optmem limit or the user exceeds their ulimit on
+locked pages.
 
 
 Mixing copy avoidance and copying
-- 
2.39.1

RE: [PATCH] [net] fix inaccuracies in msg_zerocopy.rst

[Willem de Bruijn]

nick black wrote:
> Replace "sendpage" with "sendfile". Remove comment about
> ENOBUFS when the sockopt hasn't been set; experimentation
> indicates that this is not true.
> 
> Signed-off-by: nick black <dankamongmen@gmail.com>

Reviewed-by: Willem de Bruijn <willemb@google.com>

The first error was there from the start. The second is an
inconsistency introduced with commit 5cf4a8532c99
("tcp: really ignore MSG_ZEROCOPY if no SO_ZEROCOPY")

If Documentation fixes go to net, I suggest that as Fixes tag.

Re: [PATCH] [net] fix inaccuracies in msg_zerocopy.rst

[Jakub Kicinski]

On Fri, 24 Feb 2023 09:37:55 -0500 Willem de Bruijn wrote:
> nick black wrote:
> > Replace "sendpage" with "sendfile". Remove comment about
> > ENOBUFS when the sockopt hasn't been set; experimentation
> > indicates that this is not true.
> > 
> > Signed-off-by: nick black <dankamongmen@gmail.com>  
> 
> Reviewed-by: Willem de Bruijn <willemb@google.com>
> 
> The first error was there from the start. The second is an
> inconsistency introduced with commit 5cf4a8532c99
> ("tcp: really ignore MSG_ZEROCOPY if no SO_ZEROCOPY")
> 
> If Documentation fixes go to net, I suggest that as Fixes tag.

Applied, thanks!